Treatment of asphaltic crude oils



Jan. 11, 1966 Filed Dec. 14, 1964 PENETRATION, IOOG/ SEC /77 "F 90 I00H0 120 I I I I I I BY A. c. PITCHFORD 3,228,870

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FIG. 2

1955 A. c. PlTcHFoRD 3,

TREATMENT OF ASPHALTIG CRUDE OILS Filed Dec. 14, 1964 3 Sheets-Sheet 2 ll I l I I I 3 4 5 6 7 8 9 IO SOLVENT-OIL RATIO FIG. 3

x-|o7 RED WASH CRUDE 220- 5/1 SOLVENT RATIO 0 3 /0 RED WASH cRuDE 200-mm SOLVENT RATIO LL :1 -1o7 RED WASH CRUDE A RANGELY-RED WASH SYNTHETICBLEND U 5/| SOLVENT RATIO I NVEN TOR.

I I I A.C. PITCHFORD l I l 2 3 4 BY VOLUME =7 WAT ER FIG. 4 (($077 ATTORNEVS Jan. 11, 1966 A. c. PITCHFORD 3,228,870

TREATMENT OF ASPHALTIC CRUDE OILS Filed Dec. 14, 1964 3 Sheets-Sheet 3SOLVENT-OIL RATlO TO YIELD 9O PEN. ASPHALT T 4 I l l l VOLUME 7 WATERREQUIRED F/G. 5

22 SEPARATOR MALTENES-OIL INVENTOR 1 (MIXER b 3| FRACT'ON A.C. PITCHFORDASPHALTENES A TTORNE VS United States Patent O 3,228,870 TREATMENT OFASPHALTIC CRUDE OILS Armin C. Pitchford, Bartlesville, Okla, assignor toPhillips Petroleum Company, a corporation of Delaware Filed Dec. 14,1964, Ser. No. 417,983 6 Claims. (Cl. 208-45) This application is acontinuation-in-part of application Serial No. 128,171, filed, July 31,1961.

This invention relates to the production of an improved hydrocarbon feedstock for the production of motor fuel. In one aspect it relates to theproduction of asphaltic, and resinous fractions from asphalt containingcrude oil. In another aspect it relates to a relatively simple andeconomical process for separation of asphaltic, resinous and oilymaterials from crude oils containing these materials with the productionof paving quality asphalt and improved quality feed stock for productionof motor fuel.

These improvements include increased yields, lower carbon residue and areduction in vanadium, nickel and iron contents of the oily fraction.

It is well known in the crude oil processing art that the asphaltenesand resins tend to produce coke during cracking and hydro-treatingasphalt and resin-containing oils. It is also known that asphaltenes andresins are aromatic type components of crude oils. Thus, removing bothof these aromatic components from asphalt-containing crude oils, resultsin the production of a superior charge stock for ultimate motor fuelproduction. The efiicient utilization of asphaltic crude oils orresidual fractions thereof depends upon reducing their viscosity andminimizing the yield of residual product or increasing as much aspossible the yield of motor fuel production stocks. By treatment ofasphalt-containing oils with pentane the asphalt content is reduced andthe viscosity of the extract phase is improved. However, large volumesof pentane or other closely related hydrocarbon solvents are required.The total volume of such solvent hydrocarbons can be reduced by raisingthe temperature and pressure of the treating operation. At temperaturesapproaching the critical temperature of pentane asphaltenes areprecipitated along with a portion of the resin content of the oil toyield a high melting pitch which is more easily handled than dryasphaltenes which are precipitated at room temperatures. Such hightemperatures require high operating pressures and accordingly expensivehigh pressure vessels and piping all of which contribute to high capitalinvestments.

Paving asphalts are prepared by several methods, (1) by vacuumreduction, (2) vacuum reduction with air blowing, and (3) solventextraction using normal butane, isobutane or propane. The use of propaneor the butanes yields a high quality extract oil suitable for catalyticcracking feed stock for the production of motor fuel blending stocks.The propane or butane extract is essentially a paraflinic oil containinglow concentrations of vanadium and nickel metals. However, initialinvestments for such processes are high because high pressure equipmentis required. Also vacuum reduction requires low pressures and hightemperatures. Steam costs are high because large volumes of steam arerequired in the vacuum operation. In many cases of vacuum reduction ofasphalt-containing oils paving asphalt cannot be produced without slightor excessive cracking of the asphaltic constituents.

An object of this invention is to provide a process for the separationof asphaltic materials suitable for use as paving asphalts with thesimultaneous production of oils suitable for use in catalytic crackingfor the production of improved gasoline blending stocks. Another objectof this invention is to provide such a process which is relativelysimple to operate. Yet another object of this invention is to providesuch a process for the production of paving asphalt and cracking stockwhich avoids need for use of high pressure equipment. Still otherobjects and advantages of this invention will be realized uponconsideration of the accompanying disclosure.

FIGURE 1 is a curve showing relation of n-heptane content in solventisopropanol on penetration of asphalt produced from Texas topped crudeoil. FIGURE 2 shows curves comparing penetration of asphalts preparedfrom Texas crude oils using isopropyl alcohol (isopropanol) andisobutane as selective solvents. FIGURE 3 is a curve showing relation ofsolvent-oil ratio to penetration of asphalt of a Rangely, Colorado,topped crude oil using isopropyl alcohol as solvent. FIGURE 4 showscurves illustrating the effect of water in isopropanol on control ofpenetration of asphalt from Rangely, Colorado, crude oil. FIGURE 5 is acurve showing the water content required in isopropanol to producepenetration asphalt from Rangely, Colorado, topped crude oil at varioussolvent (isopropanol-water) ratios at 175 to 180 F. FIGURE 6 is a flowdiagram showing arrangement of equipment for carrying out an embodimentof this invention. FIGURE 7 is a flow diagram showing arrangement ofequipment for carrying out another embodiment of this invention.

When it is desired to produce from an asphalt-containing oil an oil freeof asphaltic materials, such as a lubri eating oil stock, my solventextraction system is particularly appropriate, because it leaves verylittle residual oil in the asphaltic phase. In other words the yield ofthe oil fractions is high. Furthermore, my process requires lowervolumes of solvent than prior art processes, and it can be operated atatmospheric pressure and at lower temperatures than previously employed.If the purpose of the operation is to obtain a paving asphalt product, Iam able to adjust the operating conditions to product an asphalt meetingpaving specifications. I will now describe and illustrate my inventionfrom the point of view of the operating conditions which give optimumresults. Control of the process depends chiefly on the solvent additiveswhich are used with the propyl alcohol (normal propyl alcohol, isopropylalcohol) to, first, increase solvency or solvent power of the alcoholand, second, to decrease the solvent power of the alcohol. These twocategories are herein described and illustrated separately.

The employment of an additive to increase the solvent power of thealcohol is particularly beneficial when treating a crude oil containingfrom about 2 to less than 8 percent of penetration asphalt, or anasphalt-containing fraction of such crude oil. Such a crude oil orfraction thereof is treated with a solvent in a solvent-oil volume ratioin the range of about 4 to about 20, the solvent comprising about 5 to20 volume percent of a normal paratfin hydrocarbon containing from 5 to15 carbon atoms per molecule of the paraflin hydrocarbon, and theremainder of the solvent being isopropanol or normal propanol, that isisopropyl alcohol or normal propyl alcohol, at a temperature within theapproximate range of to F.

This embodiment of my invention is particularly adapted to the treatmentof asphaltic crude oils containing less than 7 percent of 100penetration asphalt. Such a crude oil is a West Texas crude oil.Ordinarily such a crude oil is topped, that is, fractions boiling up toand through the gas oils are removed leaving a thick oilasphalticresidue which in the refining art is termed topped crude.

It is frequently very diificult to produce paving asphalt of acceptablespecifications from crude oils by vacuum reduction because oflimitations of commercial units such as temperature and pressure. Vacuumreduction of such low asphalt content crude oils frequently results incracking'of the residual asphaltic material. The presence of crackedmaterial in asphalt usually makes such material unacceptable for pavinguses.

In some instances when processing low asphalt content crude oils for theproduction of paving asphalts, propane, isobutane or normal butaneextraction of the topped crude can be employed. Propane extractionrequires pressure vessels because of the very high vapor pressure ofpropane. When using isobutane or normal butane, high solvent-to-chargeoil ratios are ordinarily required for the production of acceptablepaving asphalt. Unmodified propanol or isopropanol can be usedsimilarly. However, when using propanol or isopropanol, solventrequirements may also ,be excessive as illustrated in the followingtable:

EXAMPLE I Table I .--Extractin of Texas vacuum residue with anhydrousisopropyl alcohol the ratio of 10 to l, solvent to oil, that a suitablepaving asphalt was obtained. Thus, the use of only 10 volumes of solventper volume of charge in contrast to 60 volumes of solvent per volume ofcharge oil illustrates the marked advantage of using normal heptane withthe isopropanol.

The effect of the hydrocarbon additive on the extracting power ofisopropanol is illustrated graphically in FIG- URE 1. From this figureit is noted that in order to produce asphalts having penetrations from85 to 100 requires the use of from about 12.6 to 13.4 volume percent ofnormal heptane in the isopropanol when using a solvent-oil ratio of 10to 1 at about 176 F. In the following Table III is given the minimum andmaximum as well as the optimum volume percent normal heptane AsphaltExtraction Run N0. Solvent Solvent temperature,

ratio F. Yield, wt. Pen., R dz 13,

percent 77 F. F.

IsopropanoL 10/1 178 58. 4 Too s0it 91 d0 15/1 178 46. 7 a d0 97 do /1178 51.0 .d0 93 a. do /1 178' 60.5 d0 101 (10 /1 178 31.0 110 do /1 17828. 9 94 115 In the runs illustrated in Table I isopropanol (isopropylalcohol) was used in the solvent-oil ratios given to extract the vacuumresidue of a West Texas crude oil. Only suflicient pressures wereemployed to maintain the solvent in the liquid phase. It will be notedfrom the data in this table that a 60 to l solvent-oil ratio wasrequired to yield an asphalt having a penetration of 94 at 77 F. Thesmaller or lower solvent-oil ratios yielded asphalts too soft for pavingpurposes.

In the following Table II are given results illustrating the use of thesolvent isopropanol containing paraffinic to be used with isopropanolfor the production of the stated penetration grade asphalt when using asolvent-oil ratio of 10 to 1 and a temperature of about 176 F. It is tobe understood that with solvent-to-oil ratios higher than 10 to 1, up to20 to 1, lower concentrations of nparaffin in the solvent can be used toextract the desired grade of asphalt (85 to 100 penetration) and withlower solvent-to-oil ratios than 10 to 1, down to 4 to 1, higherconcentrations of n-paralfin can be used to produce the desired pavinggrade of asphalt. Also the optimum conditions of operation for any givenfeed will vary some hydrocarbon additives to increase the solvent powerof 45 with the particular characteristics of the feed.

the isopropanol.

EXAMPLE 'II T able Il.Extracti0n of Texas vacuum. residue withisopropanol containing a hydrocarbon additive It will be noted in TableII, that in run 7 which employed only 75 volume percent normal heptanein the isopropanol, the penetration of the produced asphalt was 255,which value obviously is too high for grades of paving asphalt normallyin demand. In run 8, 13 volume percent n-heptane was employed with theisopropanol and an asphalt having a penetration of 98 was produced. Itis pointed out that this run 8 yields an asphalt quite similar to thatasphalt produced in run 6 illustrated in Table 1. Thus, by the use of 13volume percent of such a normal paraffinic hydrocarbon as normal heptanewith the isopropanol, the entire or complete solvent being used in InFIGURE 2 is a curve showing the relation between the softening point, bythe ring and ball method in degrees F. and the penetration at 77 F. ofthe asphalts of runs 7, 8, 9, and 10 in Table II.

Other paraflinic hydrocarbon additives can be used in place of normalheptane, illustrated above, such other hydrocarbons being hexane,octane, nonane, decane, pentane, cyclohexane, kerosene, naphtha or otherdistillate fraction, preferably having a boiling point or range near theboiling point of isopropyl alcohol at about atmospheric pressure. Thisboiling range of the paraffinic hydrocarbon material can be extendedsomewhat if sufficient pressure is imposed on the system to maintain thehydrocarbon in the liquid phase at the operating temperature.

The second embodiment of my invention involves the use of an additive todecrease the solvent power of the propanol and isopropanol. Thisembodiment is particularly adapted to treating crude oils which containfrom about 8 percent to about 80 percent of 100 penetration asphalt, ora fraction of such crude oil. In this case the crude oil or the fractionthereof, is treated with a solvent in the solvent-oil-ratio in the rangeof about 4 to 20 volurnes of solvent per volume of oil. This solventcomprises from about 0.75 to about 4.5 volume percent water and theremainder of the solvent is isopropanol or normal propanol, the treatingtemperature being in the range of about 175 F. to about 180 F. Toppedcrude oil fractions from Monagas (Venezuela) crude oil, some West Kansasand some Southern Oklahoma high asphalt crude oils and Rangely(Colorado) intermediate asphalt content crude oil are operable with theprocess of this invention in which the solvent power of the alcohol isreduced with water.

The production of paving asphalt from crude oils or topped crude oilscontaining large amounts, that is, from 8 to 80 percent asphalt, of 85to 100 penetration, presents a problem which requires careful control,usually a reduction in the solvent power of the extraction solvent. In

the following Table IV are given data illustrating the 'ter.

EXAMPLE III T able I V.Preparation of asphalt from Monagas topped crudeby isopropyl alcohol extraction, with and without water Asphalt Asphaltproperties Run No. Solvent ratio Temp, yield, wt F. percent Pen., R&B,77 F. F.

5/1 178 36. 7 4 182 7.5/1 179 35. 3 2 191 15 180 30. 0 219 120 49. 7 83119 110 51. 92 117 5/1 (1% HzO) 180 39.7 13 163 5/1 (2% H2O 178 42. 7 21149 5/1 (4% 1120)---- 180 49. 2 33 136 5/1 (4.5% H20 181 51.9 42 131 (5%H 184 58. 9 199 100 1 (13% NO 178 30. 2 0 218 In Table IV, it is notedthat in run 22, 13 percent normal heptane was used with isopropylalcohol at a temperature of 178 F. This run produced a very low yieldpercent of asphalt of 0 penetration at 77 F. Thus, the use of thisamount of normal heptane with the isopropanol yielded an asphalt far toohard for use as a paving asphalt.

Crude oils such as those from Rangely, Colorado, contain from about 8 to12 percent of 85 to 100 penetration asphalt. In addition, the asphaltproduced from this crude oil contains a microcrystalline wax which isassociated with the asphaltene fraction of the asphalt. The crude oilappears to be deficient in a middle-rangemo- 6 lecular weight fraction(1000-2000 M.W.) commonly referred to as resins. These compositionvariations make the control of a solvent extraction process verydifficult since with propane, a slight change in temperature or in 5solvent-oil ratio produces a magnified change in yield and grade ofasphalt.

In the following Table V are given data illustrating the marked changein 77 F. penetration of an asphalt produced in the propane extraction ofa Rangely topped crude oil fraction with small temperature changes. Whenthe temperature of extraction was increased from 191 to 196 F. thepenetration increased from 13 to 48, and a further increase inextraction temperature to 204 F. produced an asphalt having apenetration of 324. Thus, it is noted that slight changes in temperaturewith the propane-to-oil ratio remaining substantially constant yieldedasphalts having very great diiferences in penetration. In an operationusing propane as the solvent for the production of paving asphalttemperature control would be very difficult. 2

EXAMPLE IV Table V.Pr0pane fraction of 28% Rangely topped 3 crude S/Oratio Asphalt, vol.

Temperapercent Penetration ture, F. 77 F.

EXAMPLE V Table VI.16% Rangely reduced topped crude Asphalt Run SolventS/O ratio Tempera- No. ture, F. Yield, Peneweight tration percent ofcrude Isopropyl 3/1 179 10. 6 186 alcohol.

In the following Table VII are given data showing the quality of asphaltproduced when using anhydrous isopropanol with a blend of Rangely,Colorado, and Red carbon tetrachloride and the oliensis spot test.

These data of Table VII are plotted in the form of a curve which isshown in FIGURE 3. This curve shows that the 85-100 penetration gradeasphalt lies in the vertical portion of the curve and solvent-to-oilratio to produce specification.penetration of 85 to 100 would be verydifilcult to control. This difiiculty can be easily overcome by usingaqueous isopropanol as a solvent in place of the anhydrous isopropanol.In Table VIII are given the volume percentages of water used with theisopropanol and the solvent-to-oil ratios given represent the totalsolvent, that is, the isopropanol plus water.

EXAMPLE VII Table VIII.--A queous isopropanol extraction of Rangelytopped armies to produce paving asphalt The several categories ofsolvent-to-oilratios as shown in Table VIII are plotted as curves inFIGURE 4. These curves are drawn to illustrate the relation between thevolume percent of water in the solvent and penetration at 77 F. It willbe noticed that in all of these curves there is an appreciablehorizontal component, that is relative to the water content of thesolvent in the range of penetration of 85 to 100 with the exception ofthe upper curve. Thus, in view of these relatively large horizontalcomponents illustrating the volume percent water in the isopropanolextractant, the control of such an operation is relatively simple. Aswill be well understood by those skilled in the art, the control of thevolume percent of water in the isopropanol is much easier than tocontrol temperatures of the extraction column vw'thin, for example, 1,2, or 3 degrees.

Cross plotting of the data illustrated in FIGURE 4 and given in TableVIII is illustrated in FIGURE to show the volume of water necessary toproduce 90 penetration asphalt at various solvent-oil ratios fromsimilar charging stocks.

The 90 penetration values from curves 1, 2, and 3 only are used inplotting the curve illustrated in FIGURE 5. This cross plotting of thedata (FIGURE 5) shows that the water content of the isopropanol variesfrom about 0.75 to about 4.5 volume percent at solvent-to-oil ratiosfrom about 5 to 1 to 17.5 to 1, respectively, at extraction temperaturesbetween 175 and 180 F.

As mentioned hereinbefore Rangely crude oil contains small quantities ofmicro-crystalline wax which tends to degrade the specificationproperties of asphalt prepared by vacuum reduction of propaneextraction. These prop erties include penetration ratio, solubility ofasphalt in By using aqueous isopropanol these properties are improved asshown in the following example. In the following Table IX are givenpaving asphalt specifications sforthe State of Oklahoma for comparisonwith paving asphalt produced by vacuum reduction and isopropanolextraction of the identical topped crude charge "stock.

While the data given above illustrating the operation of this inventioninvolves use of isopropanol, I disclose the use of normal propanol as anequivalent of the isopropanol in all respects; However, relative to costof the material isopropanol is preferred because it is less expensive topurchase commercially than is the normal propanol.

The apparatus required for carrying out the operations of this inventionis relatively simple as will be noted in reference to FIGURE 6. Thecrude oil, or strictly speaking, topped crude oil passes from a source,not shown, through a conduit 1 into an extractor vessel 2. Thisextractor can be countercurrent, liquid-liquid contacting column or itcan be merely a mixing vessel in which the solvent aqueous isopropanoland the asphaltic oil are mixed. In such a mixer upon addition of theisopropanol and asphaltic oil contacting is achieved by use of astirring device of any suitable type. However, for most operations, acountercurrent extraction operation is preferred. Thus, from extractor 2the oily material in solution in the aqueous isopropanol is removedthrough a conduit 3 and is introduced into a still 4. In this still theaqueous isopropanol is distilled from the oil, the oil being removedfrom this vessel through a conduit 5 for such disposal as desired. Theaqueous isopropanol vapors are removed from still 4 through a conduit 6,condensed in condenser 7 and condensate is passed on through a conduit 9to a run storage vessel 10 and thence through a conduit 11 to theextractor 2. Make-up aqueous isopropanol is added to the system througha conduit 8. Since the aqueous isopropanol is specifically lighter thanthe asphaltic oil being treated the solvent is introduced at a levelnear "the bottom of the column. Upon introduction into vessel 2, thisspecifically light aqueous isopropanol passes upward in countercurrentcontact with the relatively heavy and down-flowing asphaltic oil. Thisextractor vessel can be provided with suitable liquidliquid contactpromoting apparatus. The dissolved oil and solvent pass from extractor 2through an overhead conduit 3 and this extract phase is introduced intostill 4. The asphalt containing phase with a very minor proportion ofsolvent is withdrawn from extractor 2 through a conduit 12 and is passedinto a still 13. In this vessel the small amount of solvent is removedby distillation through a conduit 14 and'these vapors are added to thosefrom conduit 6 prior to passage to condenser 7. The hot solvent-freeasphalt is removed from still 13 through a conduit 15 for such disposalor such use as desired. Relative to operations of stills 4 and 13refluxing and reboiling operations a're'not diflicult because there iscontopped crude oils disclosed hereinabove it Will then be necessary todilute the original topped crude material with 'pentan'e within atemperature range of from about 60 to about F. using a solvent-'to-oilratio of about '5 to 1 to 15 to 1 under pressures of from about 1 to 2atmospheres. This portion of the process, however, is operable over agreater temperature range such as from about 50 to about 450 F. whenusing a solvent-to-oil ratio by volume of 2 to 1 to about 100 to 1 andat pressures varying about 1 to about 50 atmospheres. As examples of theoperation of the pentane separation portion of this operation a chargeof Wafra (Kuwait) vacuum reduced crude oil was slurred with anequalvolume of pentane. This slurry was then added to an additional 9 volumesof pentane, the mixture stirred for an hour and allowed to settle forabout 16 hours. The pentane soluble material was decanted 'and filtered.The precipitated asphaltenes were washed with approximately 5 volumes offresh pentane. These washings were added to the pentane soluble materialand the pentane from the entire mixture was recovered by fractionaldistillation.

In the following Table X are given four sets of run data using pentanefor treating asphalt-containing oil for the separation of an asphaltenesproduct.

EXAMPLE IX Table X .Pentane extractions of Wafra 1025 F residuum Run NoA-l A-Z A-3 A-4 Wt. of asphalt, lbs 38. 26 36. 38. 0 38. 0 Vol. ofaphalt, gals 4. 52 4. 26 4. 5 4. 5 Vol. n-pentane, gals. 45. 9 44. 9 44.6 45.1 Solvent ratio 10. 1 10. 5 9. 9 10. 0 Temperature, F 78 80 85 86Settling time, hrs 16 16 72 48 Filtrate plus lfl-gal. wash, gals" 52. 153. 3 52. 5 52. 5 n-CE evaporation loss, gals 3.8 1. 6 2. 1 2. 6 Yields:

Asphaltenes, lbs 5. 47 5. 62 5. 37 6. 23

Asphaltenes, wt. percent 14. 8 15.6 14.13 16. 3

Maltenes, lbs 20. 84 33. 39 29. 88 33. 2

Maltenes, wt. percent 54. 4 92. 2 78. 7 87. 5 11-0 recovered, gal 43. 750. 4 47.0 47. 0 n-O loss in stripping, gal 8. 4 2. 9 5. 5 5. 5

In these four runs the solvent-to-oil ratio varied from 9.9 to 10.5 andtemperatures of treating varied from 78 to 86 F. It will be noted thatfrom 5.37 pounds of asphaltenes to 6.23 pounds of asphaltenes wereproduced from 36 to 38 pounds of original Wafra residuum. In Example A-lfrom 38.26 pounds of asphaltic charge stock, there were recovered 5.47pounds of asphaltenes and 20.84 pounds of maltenes. This quantity ofmaltenes plus the quantity of asphaltenes total only 26.31 pounds; therebeing an appreciable loss. This loss was in the maltenes fractionbecause some of the maltenes were carried into other parallel runs withpentane used for washing. In the total operation, ten individualparallel runs were made using a total weight of asphaltic feed stock of375.39 pounds. There was recovered from the ten parallel operations54.69 pounds of asphaltenes and 320.7 pounds of maltenes. These twoproducts totaled 375.39 pounds, the exact weight of the asphalticmaterial used as charge stock. This 100 percent recovery of the combinedmaltenes and asphaltenes is relatively simple because of the extremelyhigh boiling points of these materials.

The asphaltene separation by way of pentane precipitation is carried outin an apparatus as illustrated in FIG- URE 7. The topped crude materialis fed into a mixer 22 by way of a conduit 21. Normal pentane as solvententers the mixer 22 by way of a conduit 23, from a source to bedisclosed hereinafter. After sufi'icient and thorough mixing in mixer 22the mixture is passed by way of a conduit 24 to a separator vessel 25 inwhich the precipitated asphaltenes are separated from thepentaneasphaltene liquid phase. The separated asphaltenes are removedfrom separator 25 through a conduit 26 for a subsequent washing step orfor such use as desired. The liquid maltene-containing fraction isremoved from separator 25 through a conduit 27 and is passed to a still28 for recovery of the solvent pentane. This still is operated undersuch temperature and pressure conditions as to separate normal pentanefrom the heavy oily maltene fraction. Vaporous pentane leaves still 28by way of a conduit 29, is condensed in condenser 30 and condensate ispassed on through the before-mentioned conduit 23 for reuse in mixer 22.The maltene-oil fraction is withdrawn through a conduit 31 from thekettle section of still 28. Make-up pentane as required is added to thesystem through a line 32 from a source, not shown.

The heavy maltene-oil fraction withdrawn from the kettle section ofstill 28 through a conduit 31 can, if desired, be treated in the systemillustrated in FIGURE 6 of the drawing. If it is desired to separate andto recover a resin fraction from this maltene fraction then the processdescribed and illustrated hereinabove relative to FIG- URE 6 isemployed. By treating the maltenes-oil fraction free from asphaltenes inthe apparatus and according to the system of FIGURE 6, there will beproduced a resin fraction which is removed through conduit 15 from thekettle section of still 13. The oil fraction removed through conduit 5is the same oil fraction removed through this conduit when the entireasphalt containing charge oil is treated according to the system ofFIGURE 6.

While certain embodiments of the invention have been described forillustrative purposes, the invention obviously is not limited thereto.

I claim:

1. A process for simultaneously producing a paving grade asphalt and anoil suitable for catalytic cracking to produce gasoline blending stocksfrom an asphalt-containing oil in which the concentration of penetrationasphalt is in the range of 2 to less than 8 volume percent whichcomprises the steps of:

(l) contacting said asphalt-containing oil with a solvent selected fromthe group consisting of n-propanol and isopropanol containing from 5 to20 volume percent of normal parafli-n hydrocarbon of 5 to 15 carbonatoms per molecule;

(2) maintaining the volume ratio of solvent to oil in step (1) in therange of 4 to 20 and the temperature in the range of to F.;

(3) separating from the contacting a first asphaltenerich phase and asecond asphaltene-lean phase;

(4) recovering from said first phase a paving grade asphalt; and

(5) recovering from said second phase an oil for catalytic cracking.

2. The process of claim 1 wherein said hydrocarbon is principally normalheptane.

3. The process of claim 1 wherein said asphalt-containing oil has beenpreviously treated to remove a portion of the asphaltenes.

4. A process comprising contacting an asphalt containing oil with from 2to 100 volumes of liquid pentane per volume of oil at a temperaturewithin the range of about 50 to 450 F.; from this operation separating aliquid phase rich in pentane, containing a maltenes fraction, from anasphaltenes phase; recovering asphaltenes from this latter phase as oneproduct of the operation; separating from said liquid phase a maltenesfraction containing from about 2 to less than 8 volume percent of 100penetration asphalt; contacting the separated maltenes fraction at atemperature in the range of about 175 to 180 F. with a solvent selectedfrom the group of solvents consisting of normal propyl alcohol andisopropyl alcohol and containing an n-paraifin of 5 to 15 carbon atomsin a concentration in the range of 5 to 20 volume percent; from thislatter contacting step separating an oil phase rich in said solvent anda resin phase lean in said solvent; recovering oil from said oil phaseas a product; and recovering resin from said resin phase as anotherproduct of the process.

5. The process of claim 4 wherein said solvent is principally normalheptane.

6. A process comprising contacting an asphalt contain-. ing oil withfrom 4 to volumes of a solvent selected from the group consisting ofpentane and hexane per volume of oil at a temperature within the rangeof about to 450 F.; from this operation separating a liquid phase richin said solvent, containing a maltenes and oil fraction in which theconcentration of penetration asphalt is in the range of 2 to less than 8volume percent from an asphaltenes phase, recovering asphaltenes fromthis latter phase as one product of the process; separating said solventfrom said maltenes and oil fraction of said liquid phase; contacting theseparated maltenes and oil fraction with a second solvent selected fromthe group of solvents consisting of normal propyl alcohol and isopropylalcohol and containing a normal parafiin of 5. to 15 carbon atoms in aconcentration in the range of 5 to 20 volume percent at a temperature ofto F.; from this latter con tacting step separating an oil phase rich insaid second solvent and a resin phase lean in said second solvent,recovering oil from said oil phase and recovering resin from said resinphase as additional products of the process.

No references cited.

ELBERT E. GANTZ, Primary Examiner.

1. A PROCESS FOR SIMULTANEOUSLY PRODUCING A PAVING GRADE ASPHALT AND ANOIL SUITABLE FOR CATALYTIC CRACKING TO PRODUCE GASOLINE BLENDING STOCKSFROM AN ASPHALT-CONTAINING OIL IN WHICH THE CONCENTRATION OF 100PENETRATION ASPHALT IS IN THE RANGE OF 2 TO LESS THAN 8 VOLUME PERCENTWHICH COMPRISES THE STEPS OF: (1) CONTACTING SAID ASPHALT-CONTAINING OILWITH A SOLVENT SELECTED FROM THE GROUP CONSISTING OF N-PROPANOL ANDISOPROPANOL CONTAINING FROM 5 TO 20 VOLUME PERCENT OF NORMAL PARAFFINHYDROCARBON OF 5 TO 15 CARBON ATOMS PER MOLECULE; (2) MAINTAINING THEVOLUME RATIO OF SOLVENT TO OIL IN STEP (1) IN THE RANGE OF 4 TO 20 ANDTHE TEMPERATURE IN THE RANGE OF 175 TO 180*F.;